Do we consider these acceptable questions here? Or are these low quality? They come up often enough, and are reported often enough, that clarification is needed so we can have a definitive answer to refer to when dealing with them going forward.
Is this low quality?
Definitely - these questions exist only to poll and the "best" answer is necessarily a popularity contest (how many people have had a good experience with XYZ provider versus ABC provider versus a bad experience with XYZ/ABC).
I think we need meta questions/answers which describe how to shop - though the process (research, compare, then buy) is the same for any product or service, the particulars (where can I find a list of domain providers? hosting providers? etc) do change, so we'll probably end up with a handful of meta questions - in the case of domains, it'd be good to isolate the list of registrar lists, for example.
Both of those questions are covered by Q&A is hard, let's go shopping.
They could both be asked better by asking "what sort of services should I look for in a registrar when selecting between them" or some such, rather than just "What's a good registrar for x".
As danlefree states, the way these questions are currently worded they are polls at best, and are also (which is the bigger concern) often of limited long term benefit as the registrar's change their policies, or offerings, etc.